Locking mechanism for folding back rests



P 1950 F. SHIVELY 2,523,452

LOCKING MECHANISM FOR FOLDING BACK RESTS Filed March 20, 1947 6 Sheets-Sheet l IN VEN TOR.

Han/dz L. Shiva/ 1 Sept. 26, 1950 F. L. SHIVELY 2,523,452

LOCKING MECHANISM FOR FOLDING BACK RESTS Filed March 20, 1947' 6 Sheets-Sheet 2 IN V EN TOR.

F 4. Hank/11'? L. 5191i?! Sept. 26, 1950' F. SHIVELY LOCKING MECHANISM FOR FOLDING BACK RESTS Filed March 20, 1947 6 Sheets-Sheet 3 llllu xmn IN VEN TOR.

Hank/('17 L EbzVe/y Sept. 26, 1950 F. L. SHIVELY LOCKING MECHANISM FOR FOLDING BACK RESTS Filed March 20, 1947 6 Sheets-Sheet 4 I I 58 we //0 98 //2 T INVENTOR.

Frank/2'17 L. 51711151 22 i zhmhm pt- 26, 1950 F. SHIVELY 2,523,452

LOCKING MECHANISM FOR FOLDING BACK RESTS Filed March 20, 1947 6 Sheets-Sheet 5 INVENTOR.

fr Frank/1'17 L. Shiva/y Q. BY

l 26, 1950 F. L. SHIVELY 2,523,452

LOCKING MECHANISM FOR FOLDING BACK RESTS Filed March 20, 1947 6 Sheets-Sheet 6 INVENTOR. Frank/1'17 L. 5/71i/E/ iatenteci Sept. 26, 1956 'noomnemzcmimsm ron romm-e:

' i BACK- RESTS s oiai (o1. 155%;52

This invention relates r to: folding: backere'sts and is particularly concerned With foldingEbackw rests that=ma y.- be assoeiated with bed-pans :and

the like; 7

An objeet of the invention is :to previdea' fold-.- ing 'back' rest that may be aassociated with a bed'pan; which =back= rest is positive :in its action to= prevent col-lapse"when in 'supportingopositiom carr'ying outthis objectpit is a' iurtherzobject to provide a back rest that may be stored :iI'l al-li integral pocket beneath the bedpan and-may'.be moved easilyztoa iu'seabie, .or "supporting, position where it is vpositively locked until releasedandagain'iolded into'thefpocketg v Another object ofthe invention is toi provide a 'folding back re'st that includes :anovel locking mechanism that i-pern'iitsopening of the-back rest by outward andsfor'wa'rd movement and 'Sir" multaneous 1ocki'ng thereof in supporting: pOSiition whereby thefrest'may be folded only=b y continned --forward i'movement toiovei'come the-lock ing mechanism.- 'This actioniassurestthat the :rest will not collapse; .or' fold up, duringaus'e which is an important factor in the: safe iise cof the de vice.

ll'i'caliryihg iolit' the *bove :obje'cts; it'- is a*=fur'- ther' object to provide leckingmeans that trio-- tionally- "hold' the device in folded position against accidental openingimovment thereof;

An'otherobjectof 'theainventijon isltozprovide a-threei piece f olding back' rest lwhich' 'm'ay licensed in connection with the locking mechanism-aha that the' rest will be compactrin liflded :eposition and utilitarian in opened'apositiorinto the I com.- plete coinfortof the user.

I Incarrying' out the' aboveiobjects; itis still .afurther object to prbvide 'aj; groove, vertically, disposed in the-'backrestywhi'chiconforms to it-he' shape of the spinal lcoliim-n of the' iuser,-.whereb$n the use of the rest -is=comfortabie:

Furtherobjects and advantages will be zape parent, reference being made: to the accompanying drawings wherein preferred forms-of= the invention are clearlyshowns In the-drawings:

Fig.-1-is a'view in perspective of aflbedpan with a the folding back rest incorporated therein v in the folded and concealed position Fig. 2' is a View in-perspectiye pf the bedpan w t ea k e i-nrfli xtended -s orting position. 7 v I 1 Fig.3 is a plan-view of the back: rest in the folded position. 1

i a arr ew of; ha e a 0w nai "po e e e n 10. ce vin th i k r a k rest not shown).

"Figs 5-.is-a: view-ingsecton of thehacklrest fl ed-i os i cn i il n: e-line l -9i -3;--

Fi 1 a-w im e i wi "U i P a a field d ositi t k n lin -r6-Q F 1 F 7 Iise ra menta view t kee n in +1: of Fig.. 3 show-ingfthe -anti-rattle:device.- 7

Figs; -8==th pueh- 1, 'ar raem ta ew of; the iockin m cha i m- 1 used=-in n ion w theo-b'ae-k rest in different positions iromgpantiallm open to fuliy open: H

' Eigss Ii -through .13 are :fragmentary viewswf the locking ;mechanismnin .diiierent positions during; th v foldingsup' of; thezbacktresta- 1 EE ig. :l' il'is a viewiin sectiomtakenzorrclinewl4-4145 ot EiaHiO; v g iF i'gs 15 is a view in sectioniofian assembly tail.bmhelockingrmechanism and z I Fig; l6- is a viewroffthe spring usediin'ltheuaw Sam-buy showii in -=15 in its free ipositiori and in its aesenibled positiom ishowri in dotted-shims; 17 throu'ghl 19h show the back-rest rper se ihits-'varioiis positions fi 'om fullyclosed to inl l'yi open sition with' the lcicking meGhaniSm mE movedior ciarity a F'is'.- 20- throiigh'22 s ow -iri detai-Fthe action of hinges used' in connection-with1the =hack=pow mm of the backrest"inpartia11y-=closed to l o fieri li in' 'o he a r; r iiig' use and" which-as ures that the ba o w'm'remain iIib-a'ck supporting position iiit i r i b manua man ul n to 2 'n position at which time the action of the lock ng deirice'isovercome r it siot nd se tna wme h s back F- that it" may also sber isearin connection "with; ihfiltitude of applicationswwhere .a seat ,\ws7ith,ar

portaloleseat'forga boat H H I w a child or as a portable seat iorfnse inia still In ea -c se ra 9m h ee -wi M back rest .wil1',.lde useiiil W In use of the back rest with a bedpan, I have made several other improvements over my original design which are useful and desirable. For example, I have provided an anti-rattle device so that when the bedpan is in folded position that it may be carried about without noise. I have also provided a friction operated lock that holds the folded back rest in place within the bedpan to prevent accidental displacement thereof when the pan is being carried from its place of storage to the patients bed, or vice Versa.

Another improvement of particular utility is concerned with a. vertical groove in the back rest which is shaped to conform to the contours of a human spine so that hospital patients that are in an emaciated condition may sit on the pan with complete comfort and without chafing their thoracic spinous processes against the metal back. This factor is of real importance from a comfort angle and persons who have used my improved bedpan can readily differentiate it from the prior type that does not include such a groove.

Basically, the improvements in the bedpan over my prior type of pan are directed to the folding back rest which is improved in many respects to provide a smoother operation with a positive action. This is important since if the back rest is not positively locked in position, it may collapse while a sick and weakened patient is using the bedpan and thereby cause the user to be thrown tothe bed or from the bed. Thus, it is of the utmost necessity that the back rest be positive in its action and bench-collapsible except when properly manipulated by the nurse or attendant. The present .mechanism assures this action through the inclusion of a novel type of locking mechanism which can only be operated in one direction and which. cannot be caused to move backwards. Thus as the back rest is raised into back supporting position, it passes through a series of lcking movements that will prevent backwards motion. .After the rest is in the fully opened position, it can onlybe closed by continued upward movement past the final locking device whereupon the rest will fold up into the base of the pan. A patient cannot jar or jolt the rest into this upwards movement, this can only be accomplished by a positive upwards pull of appreciable movement so that accidental fold- .ing up of the rest is an impossibility.

The locking mechanism is incorporated in a ca'mrriing device which maybe carried by the back rest'that slides from closed to open position along substantially -horizontally disposed guide 7 ways that are supported on orare integral with a frame carried and fixedfwithin the pocket'beneath the bedpan or they may be carried only by the bottom of the bedpan per se. 'Thus the back rest may be easily manipulated from one position to another by sliding movement over the guides.

Referring particularly to the drawings, Fig. 1 shows a bedpan 2flwhich includes a' container portion 22 having a receiving aperture 24 therethrough. A pocket 26 is provided which extends a" substantial distance beneath the container 22 as shown in Fig. 5. Within the pocket 26 is a back'rest assembly 28 shown in folded position in Fig. 1. The particular shape of the bedpan is of interest. In this connection, it will be noted that the rear portion of' the top wall thereof, as designated at 30, is inclined downwardly at approximately a 15 angle so that the user will experience greater comfort. This design permits the patient to be placed on the pan with greater 4 ease as it facilitates sliding of the pan beneath the user.

Fig. 2 shows the pan 2!] with the back rest assembly 28 in extended position. In this position it will be noted that the rest is preferably made in three sections designated at 32, 34 and 36. This design permits a higher back rest to be used which will fold up into the required space. It is apparent that one or two sections only may be used if desired in certain application, without in any way departing from the scope or spirit of my invention, however in connection with a bedpan,

I prefer three sections, as shown. The portions 32 and 36 each include a hand grip 38 and 40 respectively which grips superimpose when the back rest is in folded position as shown in Fig. l. The portions 32 and 56 are preferably formed from a relatively strong metal, such as steel, stainless steel, etc., which is cross ribbed, as shown, for added rigidity. The intermediate portion of the rest 34 is merely a pair of foldable channeled side rails or extensions 42 and 44 which interlock with the remaining back rest portions in a positive manner as Will be explained hereinafter. The top portion 36 includes a vertical channel or groove 46 therein which conforms to the contour of a human spine and thus adds comfort in the use of the device as explained herein.

Referring particularly to Fig. 19, the back rest assembly 28 is carried by, and is slidable in, a guide plate assembly or frame 50 which includes a bottom plate 52 that has two identical upwardly extending projections or sides 54 and 55 thereon. These projections are each disposed at right angles to the surface of the plate 52 and carry the guide ways 58 and 60 for the back rest therein together with a locking notch 52 for the back rest when in folded position. The bottom plate 52 and the projections 54 and 56 may be integrally formed out of a single piece of metal although it is apparent that three or more pieces of metal could be successfully used. The guide plate assembly is immovably positioned within the pocket 26 in the bedpan 20 as by welding,

riveting etc. or the plate may be positioned removably by headed screws or rivets 5i which slide into notches in the projections 54 and 56, as shown in Fig. 3, and forms a substantially integral part of the bedpan when assembly is complete.

A locking device 10 is shown in various positions of operation in Figs. 8 through 13. Two of such devices 10 are provided on opposite sides of the back rest 28 and associated with identical extensions 12 carriedby the portion 32 of the back rest 28. For the sake of clarity one locking device only will be described, it being understood that another identical device is provided for the other side of the back rest. The device ii! includes a pair of swingable levers l4 and 76 which are pivoted at 13 on the side projection 54 of the guide plate assembly 50 and which are yieldably held in position by springs 15 and 1'! respectively. The levers cooperate with a cam 18 carried by the extension 12. The cam-l8 rides in and is guided by a slot or groove 58 in the projection 54. In order to guide properly the back rest, a second cam 82 is providedand is carried by the extension 72 which cam 82 is guided in a second slot or groove 60 in extension 54. The slot 55 has no function in the locking device being providedonly as a guiding means for the back rest.

tirety in Figs. 1'7 through 19.

notch- 88*. Inth-is-p'osition the-back*-rest is lild' 'in' 'foldejd" position through '5 the inherent resiliency of-theslat 9'4. "When'thesrestis'to be" brought to'supporting or openposition, the operatorgrasps the superimposed-hand grips 38 and slat-"94 and thus cause the cam 18 to bediseng'a'ged from -'notch 88' and be free in the slot 581 In jthisposition the slot 94 is no'jlongerengaged with thehuinptll so -that action is free.

At the right endof slot 58 is a. substantiallytriangular shaped aperture-96'having ano-tch 98 atit's extreme lower 'corner. The triangular shaped-edges ofthe aperture 96act'as camming surfaces-inconnection with cam lfl as will be described hereinafter;

In'operation, from a folded position, the cam 'lfif ri-ioves towards the right end of slot58 until it engages the notched surface- I00 onlever16 as shown in Fig. 9. Continued movement causes lever 16-to yieldably move toward the right and permit the cam 18 to pass and drop into notch J 98 During the movement of lever 16, lever" 14 moves concurrently due to engagement of lever lttherewith to open the notch 98 and permit cam l8todrop therein, asshown inFigs101-- In this position the back rest 28 is in supporting position and cannot move backwardly or collapse since the lever 16 has moved to a locking positionas noted in Fig. 10. During the aforementioned movements the back rest 28 is being unfolded to fully extended position as noted" in Figs. 19 and 19a. The specific functions of the hinge I04 are shown more clearly in Figs. 20 through 22. l

'In-order to fold up the back rest 28, further upward and outward movement thereof is re-' quired :which' causes cam F8 to operate against cam surface IilZ-"on lever 'Mfand cause the lever I4 to yi'eldably move towards the right as shown inf'F'ig'. 11 where the lever 14 moves alone and permits the cam '18 to pass-upwardly into notch I06 carriedby lever M. At this point, pressure exerted *against the backrest 28 to push the folded assemblyinto the receiving pocket 26 causes the cam 18 to simultaneously press against the surfaces I08 on projection 54 and H0 on lever 1.6 whereupon levers 14 and 16 yieldably move towards'i therig'ht. to permit. the cam 18 to again enter slot 58. As soon as the cam passes any ofthe camming surfaces on the levers, and Bpt h'e levers assume their normal positions due to springs TE and TI and thus close the slots against reverse movementof the cam. In this manner, the cam i8 can only move in a clockwise direction through the cycle of operationwhich prevents collapseof the back rest; i

In the folding movement of the back. rest lfi.

it,-is;necessa r.y to lift the rest anJapprecia'bIe distanoe to overcome the locking mechanism, in fa'ct'thesdistance between thecam 82, and the topiof slotfitasshown in Figs. 10 through 12. With this movement required it is apparent that no accidental collapse is possible.

The earns 18 and 82 are preferably of a roller type to reduce friction and are held in place in the channeled member 12 by a spring lock III which- 1s resiliently:- positioned lnth charmer oil the member-'12 and-'which has notehes M2 and l- I 4 in ears thereof that clip into grooves; in the! canirollers 1-8 and 82.

Infolded positiomthe; back' rest-28 is engaged;

in notch-62in the side projections 54 and. 56:-

of the base plate-assembly;- 50 i this position;

hump 90 acts asa pivot and-the entire back resti swings around the contact point 1 between the humpEHl-andthe slat 94-to force-the cam 18 upwardly' into 'notch 88 a'nd" to force the roller pivots" l2t-downwardly'into notch62ilnstead of liumptll a'cting-as a pivot, a pain of curved canimingsurfaces l2l, carried by the; sides *ofs'ection'36 of the back rest-maybe used, as shown in Figs. 5 and '6. In-this embodiment the humpllfl raises-the front end of' -the back and causesit to swing about surfaces l2l to pivot therear-end of the folded-backrestdown-' wardly: It is apparent, however-,thatthe hump 90 and-slat 94 may be so positioned-to cause the action independent of the surfaces I 2 I if desired;

In order to prevent any noise or rattling-in this position; anti-rattledevice 124 are incorporated inthe assembly and one of these is attached to each of the projections Hand 56. The antirattle" devices I24 each consists of a swingable lever l26' pivoted at 128 and includinga cam-'- ming surface l3fl-thatjyieldably bears against the rollers I235 A spring l32 holds the lever tightly against the roller I20 sothat the entire folded back rest '23 is held under pressure, thus 1 preventingany rattling thereof.

1. A self-locking mechanism, comprising incombination, a bas structure including a substantiallytriangular cam track therein, a part to be locked in substantially upright position, a cam carried by said part and movable in said track to one of three corner positions, two levers each pivoted" in the same direction on the base structiire yie'ldable means holding the levers in' positionto oppose free movement of said cam in one clockwise direction and each opposing movement of said cam in a direction counterclockwise to said one clockwise direction, wherebysaid cam when moved to anyone of the three extreme corner positions of said track'is only movable" therefrom in said one clockwise direction.

2; A. self-locking mechanism comprising in combination, a base structure, a part to be locked in a substantiallyuprightposition, a cam carried by'.said.;part,'a track in said structure; for said earn, a "lever," fory'ieldably opposing said move ment of said cam in said track in one clockwise direction and for positively opposing movement I 7 of said cam insaid track in a counterclockwise direction, a second lever movable with said first lever upon yieldable movement thereof in said one clockwise direction and independently yieldably movable to permit passage thereby of said cam after the cam has passed said first lever, said second lever including a stop thereonfor pos itively preventing counterclockwise movement of said cam in said track after said independent movement of said second lever, said cam being movable to itsinitial position through yieldable movement of said first lever when said cam has passed said stop whereby the cam may be moved to any one of three positions consecutively and is prevented from backward movement after attaining any one of said three positions.

3. A self-locking mechanism, comprising in combination, a base structure includinga cam track therein having'three extreme corner positions, a part to be locked in substantialy upright position, a cam actuated by said part and movable in said track, apair of locking levers yieldably opposing free movement of said cam in said track in one clockwise direction and positively opposing movement of said cam in a counterclockwise direction to said one direction, said cam being movable successively to each of said three extreme corner positions in one direction and being locked against movement in any other direction.

4. A self-locking mechanism comprising in combination; a base structure including a cam track associated therewith having three extreme corner positions a part to be locked in a substantially upright position, a cam actuated b said part and movable in said track, two latches yieldably opposing free movement of said cam in one clockwise direction only and positively opposing movement of said cam in acounterclockwise direction, said cam when moving from a first to a second position causing both of said latches to move, said cam when moving from said second to a third position causing only one of said latches to move, said cam when moving from the third .to the first position causing both of said latches zto move, said movement of said latches permit- :ting successive movements of said cam to said extreme corner positions and simultaneously preventing said cam from backward movement.

5. A folding back rest comprising, a plurality of hinged sections movable from a back supporting position to a folded position, a base for carrying said back rest inculdinga cam track therein, a cam associated with the back rest and movable in said track, a locking device on said base and associating said back rest and said base comprising, a plurality of yieldable latching levers adapted to be operated by said cam for latching the cam and its associated backrest in successive positions of fully folded and fully open, said device locking the back rest against accidental folding and being operable to permit premediated folding thereof only by further opening movement of said back rest prior to folding up of the back rest. v

6. A folding back rest comprising, a base having opposed upturned sides thereon each of which includes two guide tracks associated therewith, a back rest collapsible onto said base in folded position and disposed substantially perpendicular thereto in open position, a pair of spaced cams carried by each side of the back rest, one of said cams being journalled in each of, said guide 8 tracks, and locking means associated with the base adjacent to the back thereof and cooperating with one pair of tracks and cams through spring actuated latches to prevent the back rest from accidental collapse after it is in open position, said back rest being opened by manipulation thereof in a direction upwards and outward of the base, said locking device locking the back' rest against accidental collapse until the back is again raised upwardly to actuate the said latches to release the cams and permit collapse thereof.

7. A locking mechanism for use with a folding back rest comprising in combination; a base structure having substantially perpendicular opposed sides thereon, each of said sides having an elongated guide track associated therewith adapted to guide the back rest from one position to another position thereof, said tracks each having a first notch adjacent one end thereof and a second notch disposed in each of the perpendicular sides, said second notch being spaced apart from said track at the opposite sides from said first notch a back rest adapted to be folded into said base from an open position and including opposed side members thereon, a pair of cams, one of which is carried by each sid member adjacent on end thereof and adapted to ride in said track for guiding the back rest in its movements and further adapted to fit into said first notches, a second pair of cams one of which is carried by each of said side members, said second pair of cams being spaced remotely from said first mentioned pair of cams and being adapted to fit into said second notches, a camming hump associated with said base, and a cross member connecting said side members and being disposed between said first and second pair of cams and adapted to ride up onto said camming hump when the back rest is in folded position whereby the first mentioned pair of cams are forced into said first notches while said second pair of cams are forced into said second notches for locking the back rest in folded position.

8. The locking mechanism as claimed in claim 7 wherein an anti-rattle device is included comprising a pair of spring pressed levers carried by opposite sides of the base each of which is adapted to press against one of said second mentioned cams for holding the cams in tight relation to said notches and thereby preventing rattling of the mechanism.

FRANKLIN L. SHIVELY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

